Well, I have regrettably discovered today why it's not a good idea to leave birdseed in the windowsill. I'd thought to leave seed on the porch roof just down from my window. Fine. Lots of birds have discovered the place and I can watch them while typing here.

But I became greedy for birds and began leaving seed on the windowsill right here at my computer. All went well. Even a few tree rats discovered the stash and I began to see squirrels going after the sunflower seeds, scaring away the birds, of course, but only for a while.
A piliated woodpecker visited, not three feet from my eyes. Extraordinary! Just this morning.

But:

By this afternoon there was a kind of feeding frenzy and a few birds flew into the window. So, I won't leave seed there anymore. The roof, which is about six feet away, will have to do. Live and learn.